Strand-tension-control mechanism



June 5, 1928.

C. R. AVERY STRAND TENSION CONTROL MECHANISM Filed April 28, 1924Patented June 5, 1928.

UNITED STATES PATEN T OFFICE.

GORDON ROBERT AVERY, 01' LA GRANGE, ILIiINOIS, ASSIGNOR TO WESTERN ELEC-TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OI NEWYORK.

STRAND-TENSION-CONTROL MECHANISM Application fled April as, 1924. SerialNo. 708,382.

This invention relates to strand working mechanisms, and morearticularly to tension control mechanisms t lerefor, which serve tomaintain a strand under a substantially uniform tension as it iswithdrawn from a supply spool.

An object of this inventlon is to maintain a strand under asubstantially uniform tension as it is withdrawn from a supply spool, ins ite of the varying diameter and welght of t e spool, inertia atstarting, momentum at stopping, and the intermittent, irregular or jerkyspeed at which the strand 1s be1ng withdrawn therefrom, withoutstretching or breaking the strand or injuring the coating, covering, orinsulation thereof.

Another object of this inventlon 1s to provide a stranding machine withan improyed mechanism for automatically maintaining the strands under apractically uniform tension as they are unwound from the supply spools.

Other objects and advantages of the present invention will becomeapparent in the following detailed description, and W111 be particularlypointed out in the appended claims.

For convenience throughout the specification and claims, the word strandwill be taken to include any elongated material, such as wire, thread,string, rope, ribbon, cable, etc.; and the word spool will be taken toinclude any rotatable object upon which a strand may be wound and fromwhich it may afterwards be unwound.

One embodiment of the invention may comprise a pivotal member carrying aguide roller which is positioned to normally engage the strand, saidpivotal member being operatively connected to a friction brake memberwhich normally engages the head of the supply spool. Variations in thetension or pull on the strand are partially taken up by the pivotalguide member which at the same time operates to vary the braking effeetof the brake member, thereby varying the speed of the supply spool so asto maintain the tension of the strand substantially uniform.

While the invention is herein illustrated and described as applied to astranding machine, it is apparent that the features thereof areapplicable to various other forms of strand working machines withoutdeparting In the accompanying drawings which i illustrate one embodimentof the invention,

Fig. 1 is a front elevation, partly in section of a stranding machinewith a tension mechanism embodying the present invention mountedthereon;

Fig. 2 is a fragmentary front elevation of the tension mechanism shownin Fig. 1, and

Fig. 3 is a fragmenta detail view of one of the sup ly spool hea s and apart of the brake mem er.

Referring now to the drawings in detail, in which like referencenumerals are employed to designate similarparts in all the views, 10denotes, generally, one unit of a stranding machine, such as is usedinthe manufacturing of telephone cable's. A drum 11 is revolvablyjournaled in bearings 12 and 13 by hol low end trunnions 14 and 15respectively. The bearings 12 and 13 are rigidly supported on uprightstandards 16 and 17 respectively which are reinforced b a cross member18. Guide rings 19 an 20 are mounted on the drum 11 on op osite sides ofthe bearing 13 in such a positlon that the openings therein are inlongitudinal alignment with the opening in the trunnion 15. A polisher21 is supported on a bracket 22 secured to the standard 17.

Referring now to Figs. 1 and 3, a pair of annular bands 23, are rigidlysupported about the drum 11 and are provided with a plurality of uallyspaced bearings 24 in which a plura lty of supply spools 25 arerevolvably mounted. The periphery of the drum 11 comprises a pluralityof equally spaced angle irons 26, there being one for each supply spool.Since the stranding machine disclosed is of a well-known type and formsno part of this invention, it is thought that a further detaileddescription thereof is unnecessary.

The improved tension control mechanism, which serves to maintain thestrand under a substantially uniform tension as it is withdrawn from thesupply spool, will now be described; an arm 27, carrying a guide roller28, is pivoted at 29 to the angle iron 26 and is resiliently connectedby a tension spring 30 to the vertical leg of an angular member 31, theother leg of which is pivoted insulation thereof. It should beunderstood at 32 to the angle iron 26'. One end of a ten;

. to normally engage one of the heads 37 of g the supply spool 25. Asuitable stop 38 is 27. Both the arm 27 and member 31 are provided tolimit the movement of the arm provided with a plurality of apertures 39and 40 respectively which serve as adjusting means for properlyregulating the tension of the springs 30 and 33.

The operation of the mechanism above described is as follows: The drum11 is revolved by any suitable source of power (not shown) throughgearing indicated at 41. Strands 45, drawn from the supply spools 25,are passed over the guide rollers 28, through the guide rings 19 and 20,and then through the olisher 21, at which .point the stranding ta esplace. Any suitable mechanism, such as a power driven capstan (notshown), may be employed to withdraw the strands from the supply spoolsand pass them through the above mentioned guide rings and polisher..Since the tension of the spring 33 is greater than the tension of thespring 30, under normal operating conditions the brake shoe 36constantly engages the head of the supply spool, which, while permittingits free rotation, prevents spinning thereof. By this arrangement anyslight variations in the tension or pull on the strand are taken up bythe spring 30 without varying the braking effect of the brake shoe 36.However, larger variations in'the tension or pull on the strand producegreater unbalances between the 'sprlngs 30 and 33 so that the arm 31 iscaused to swing to the left or right on its pivot 32, thereby increasingor decreasing the braking effect of the brake shoe 36 until the tensionof the strand is again restored to normal.

It is apparent from the above description that the mechanism disclosedis simple in construction and in operation and performs the function forwhich it is intended without in any way stretching or breaking thestrand'or injuring the coating, covering, or

t ereof are applicable to various other forms of strand working machinesand the invention should be limited .only by the scope of the appendedclaims.

What is claimed is:

1. A mechanism for maintaining a substantially uniform tension in astrand being withdrawn from a supply spool, comprising a brake memberengaging the face of the spool head, a pivoted lever associated withsaid brake, two springs connected with said lever and disposed atopposite sides thereof and acting in opposite directions, a sheave overwhich the strand passes, and pivoted means carrying said sheave andresponsive to the tension of the strand for directly acting on one ofsaid springs for varying the position of said pivoted lever andconsequently the braking eflect of said brake A 3. 'A mechanism formaintaining a substantially uniform tension in a strand being' withdrawnfrom a supply reel, comprising a brake mounted on one end of .a leverfor controlling the rotation of the reel, a spring attached to theopposite end of the lever for engaging the brake with the reel, a secondspring attached to the lever for disengaging the brake, a pivoted armoperatively connected with said lever through said second spring, asheave carried by said arm.

for guiding the strand, and a stop for limiting the movement imparted tothe arm by the springs.

4. A mechanismfor maintaining a sub-- stantially uniform'tension in astrand being withdrawn from a supply reel, comprising a brake for;engaging the supply reel, a lever arm supporting the brake, a s ringattached thereto tending to engage the rake with the reel, apivoted arm,a second spring attached to the lever arm tending to disengage thebrake, said second spring attached to and actuated by the pivoted arm,and a sheave over which the strand passes carried by said arm.

In witness whereof, I hereunto subscribe my name this 16th day of April,A. D. 1924.

GORDON ROBERT AVERY.

Ill

